This invention relates to the creation of X-ray images without the use of conventional X-ray film and is particularly adapted for use with radiographic systems in which an X-ray source produces electrons and/or ions to form an electrostatic image suitable for printing. Such a system, commonly referred to as ionography or electron radiography, utilizes an X-ray opaque gas or liquid between two electrodes in an imaging chamber to produce a photoelectric current within that chamber which is a local function of the X-rays entering the chamber. The variation in the photocurrent due to the variation of X-ray intensity exiting from the illuminated object is commonly recorded on a dielectric sheet or receptor, and the latent electrostatic charge image is made visibly by xerographic techniques. For further information on the basic process, reference should be made to U.S. Pat. No. 3,774,029 entitled Radiographic System with Xerographic Printing.
The conventional electronradiographic system utilizes a gas at high pressure or a liquid at atmospheric pressure in the imaging chamber as an imaging medium. Because it is necessary to remove the receptor sheet from the imaging chamber for development of the latent electrostatic image, it is essential both from a financial and chemical purity standpoint that the imaging medium be removed and stored between exposures. This requires an imaging chamber which is easily accessible for the transport of the receptor, and a gas or liquid recycling system to preserve the imaging medium. The need for the transport of the receptor through the imaging chamber affects the design of the chamber, particularly with respect to strength and pressure sealing. Because of the relatively low static charge of the latent image, special liquid toners must be used, which require more complex handling than conventional liquid toners known in the art.